Stock selecting apparatus for use with paper machines



1945- E. A. POIRIER STOCK SELECTING APPARATUS FOR USE WITH PAPER MACHINES 2 Sheets-Sheet 1 Filed May 19, 1942 Oct. 9,1945.

E. A. POIRIER I 2,386,632

STOCK SEIJECTING APPARATUS FOR USE WITH PAPER MACHINES Filed May 19, 1942 2 Sheets-sheaf 2 9 m; 1 I I I I J I I l I I i I I 5' @L/{ I z I I 7, I I I I I I O I I I I I l Patented Oct. 9, 1945 SELECTING APPARATUS FOR USE WITH PAPER MACHINES Ernest A. Poirier, Waterville, Maine Application May 19,1942, Serial No. 443 568 6 Claims. An. important cause of flaws and defects in paper is the presence of dirt in the stock. Not- 1 withstanding the pains taken in the preparation of paper stock for delivery to the papermaking machine to remove the particles of material too coarse to go into paper and other foreign sub stances which unavoidably become associated with the fiber, it frequently happens, nevertheless, that particles of dirt are present in the stock when it is delivered to the Fourdrinier wire or to the paper making cylinder. Some of these particles of, foreign materials are heavierpthan water and some are lighter, but both are equally objectionable in the finished sheet. H, v 1 The present invention is especially concerned with the. problem presented by these considerations, and it aims to devise a thoroughly praC- tical solution for it. The invention involves both a novel method of removingjrom paper making ,stock these particles of dirt that cannot be taken out by the c'ornmon screening operations. It also includes a novel apparatus operating'in accordance with this method.

The nature of the invention will be readily understood from the following description when read in connection with the accompanying drawings, and the novel features will be particularly pointed out in the appended claims.

In the drawings: Figure 1 is a plan view of an apparatus constructed in accordance with the, invention;

Fig. 2 is a vertical, longitudinal sectional view of the apparatus'shown in Fig. 1; r

Fig. 3 is a vertical, transverse/sectional view taken approximately on the line 3.3, Fig. 2;

Fig. 4 is a plan view of the'right-hand end por tion' of a trough like that shown in Fig. 1 but prov1ded with a somewhatdiiferent arrangement for carryingaway-the floating dirt;

Figs. 5 and 6 are vertical, sectional views apabove and below the deflectors.

-or in any other convenient manner. Positioned transversely in this trough are several deflectors indicated at 4, 5 and t, respectively, each of tapered or triangular cross-sectional form, and

each extending across the trough from one side thereof to'the other, with their thinner edges; pointing up-stream. An outlet or discharge pipe I carries away the good stock and it is equipped with a valve 8 so that in connection with the usual controlling apparatus used to regulate the I delivery of stock to the trough through the pipe 3 a substantially constant level of stock will be maintained in the trough and that level will be 'suflicient to keep the deflectors 4, 5 and 6 continuously submerged. The discharge or delivery conduit l leads from an outlet header or conduit 10, which is similar to the deflectors l, 5 and 6,

and is similarly positioned, but it is provided with a narrow intake slot l2 extending across the trough from one side thereof to the other. This inlet. is located immediately behind the rearmost deflector 6 with the rearward side of the latter extending both above and below the inlet.

It should be observed that the deflectors are positioned a few inches abeve'the bottom of the trough s0 that'as the stock flows through it these members 6, 5 and 6 divide the portions of the stream in which they are positioned into upper and lower portions or layers flowing, respectively, Their action is such that they tend to direct the light weight dirt into the upper layer or layers of the streamand proximately on 'thelines 5--5 and 6-6, respectively, of Fig. 4'; and

'Fig. 7 is a view similar to Fig. 6 illustrating a iurther modification.

Figure 8 is a vertical, transverse, sectional view of a'modified form ofthe deflector.

The present invention provides a method in which the lighter dirt is floated ofi from a stream of stock in which itis carried, while the heavier I dirt is settled out or trapped, and both are thus separatedfrom the main body of good stock.

Referring to the drawings, the construction there shown comprises a box or .trough 2 adapted to guide a stream of paper making stock which may be deliveredtl'iereto by the supply pipe 3,

to guide the heavier particles intothe lower layers flowing along the bottom of the trough. Such separation of the two kinds of dirt into the upper and lower strata of the stream may be further facilitated by so controlling the rate of flow that a gravity separation of the heavier dirt into the lower layers also will occur. The result of this action is that when a given cross-sectional portion of-the stream reaches the outlet header 10 the two kinds of dirt will be very thoroughly segregated from each other and floating dirt will beguided over or above the outlet slot l2, while the heavier dirt will be guided below it.

It should alsobe observed thatsthe header l0 formsa kind of dam or obstruction at the tail portion of the trough. A tailings discharge pipe l3 opening into the bottom of the trough at this end carries away both the lower layer of the stream,'with the dirt entrained therein, and also the upper layer which overfiowsthe rearward edge of the header l0. Another pipe l4 carries ,this material to the intake end of a rotary pump l5 which'discharges it through either of the pipes IE or ",as desired. The former may lead to a settling tank, to some earlier preparatory machinery, or to any other desired point, while the latter conducts the material back into the trough 2. Both of these pipes IG-and II are equipped with control valves by means or which the delivery of the stock to one point orthe other can be determined at will. A short vertical section of pipe l8 leads downwardly fromthe Junction of the pipes I3 and I4 and forms a trap inwhich the very heavy particles of dirt will collect. This pipe-also is equipped with a valve 20 by means of which the trap may be cleaned out whenever desired. Additional valves 2| and 22 may be connected into the system to facilitate control, washing out, and the like. 1

a As above indicated, the. rate of flow of the stock through the trough should be sufficiently slow to facilitate, or at least to permit the, separating action above described. In some cases, due to the nature of the dirt, the rate of flow must be very slow as, for example, one-half or onethird of a foot per second, while in other cases it can be speeded up to in the neighborhood of five or six feet per second, or possibly somewhat more. With those forms of dirt having a specific gravity close to that of water, the velocity of flow has a very important bearing on the operation of the apparatus, and unfortunately much of the dirt which proves more troublesome in paper making is of this variety. With any but extremely slow speeds the deflectors should be streamlined, somewhat as indicated at IS in Fig. 8, in order to avoid excessive turbulance r eddying immediately behind them, I I

In the construction shownin Figs. 1 to 3, there 7 is some tendency for the dirt to collect in-the apparatus, thus requiring a shutting down and cleaning out of the apparatus at the end of, say, eight or. ten hours run, or possibly longer, de-

- pending upon circumstances. And this is not ob- However, the

2 and the uppermost layer of the stream flows over a dam 23 and down an apron 24, carrying the floating dirt with it. The water and dirt so discharged are led away through a, pipe 25 into the pipe l3 corresponding to that shown at H8 in Figs. 2 and 3. Preferably the apron is tilted, as indicated, for example, in Fig. 6, to facilitate the drain-off of the surface water.

Also, in order to deal with the tendency of the heavier dirt to collect in the right-hand corners ofthe box, the section of the bottom from which the discharge pipe l3 leads, may be inclined, as shown at 26 in Fig. '7. such inclinations starting at both right hand corners and leading downwardly to a middle point at'which the pipe I3 is connected.- These modification permit a longer period of operation without interruption for washing or cleaning.

.While I have herein shown and described preferred embodiments of my invention, it will be evident that the invention may be embodied in other forms without departing from the spirit or scope thereof. f

Having thus described my invention. what I desire to claim as new is: 3

Y in said trough transversely. thereof in position to be submerged in said stream, each of said deflectors being wedge-shaped and positioned with its thin edge directed upstream, a delivery con- I ,duit having an intake positioned near the tail end of the trough at a substantial distance below the surface of the stock therein, said intake being in the form of a narrow slot located transversely in the trough, a deflector positioned immediately in front of said intake and having portions extending both above and below' said slot, means opening into the bottom of said trough in the neighborhood of said intake for conducting away the heavier dirt which is carried along the bottom of the trough by said stream and means additional to said last mentioned deflector for diverting floating dirt away from said intake.

2. In an apparatus for separating-dirt from paper making stock, the combination of a trough forguiding a stream of said stock along a predetermined path, a plurality of deflectors located in said trough transversely thereof in position to be submerged in said stream, each of said deflectors being wedge-shaped and positioned with its thin edge directed upstream, a delivery conduit having an intake positioned near the tail end of the trough at a substantial distance betions extending both above and below said slot,

means opening into thebottom of said trough in the neighborhood of said intake for conducting away the heavierdirt which is carried along the bottom of the trough by said stream, and a dam positioned across said trough near said intake slot and over which said surface layer flows I 'paper making stock, the combination of a trough 1. In an apparatus for separating dirt from paper making stock, the combination of a trough for guiding a'stream of said stock along a pre deflectors being shaped to exert a separating action on the lighter and, heavier materials carried by the stream serving to divide the portions of the stream in which they are located into upper and lower-portions containing, respectively, the lighter and, heavier impurities, and a delivery conduit having its intake in said trough at an intermediate level in the stream, oneof said deflectors being positioned in front of and close to said intake of the delivery conduit.

4. In an appartus for separating dirt from paper making stock, the combination of an elongated trough for guiding a stream of said stock thereth'rough, a delivery conduit having an intake positioned at an intermediate level in said stream, a deflector positioned in said trough upstream from said intake and serving to divert heavy dirt into the lower portion of the stream and the floating dirt into the upper portion, and means for diverting the surface portion of said stream,

together with the dirt carried thereby, away from said intake end, whereby the portion of the stream entering said conduit will be kept sub stantially free of both heavy and floating dirt.

5. Inan apparatus for separating dirt from paper making stock, the combination of an elongated trough for guiding a stream of said stock therethro'ugh, a delivery conduit having ,an intake end positioned at an intermediate, level in said stream, said intake end being in the form of a narrow slot locatedhorizont'ally in the trough and extending transversely thereof. a dam down stream from said slot over which the surface layer of said stream is discharged, and means for continuously draining oi! the bottom layer of stock, together with the heavier dir't carried thereby.

6. In an apparatus for separating dirt from paper making stock, the combination of an elongated trough for guiding a stream of said stock therethrough, deflecting means submerged in said stream of stock serving to divide the stream into upper and lower portions, both portions being of substantial depth and the upper portion carrying the lighter impurities and the lower portion the heavier impurities, a delivery conduit having 16 an intake slot positioned horizontally in said and additional means positioned downstream from said intake slot for dischargin the floating impurities.

ERNEST a Pomrm. 

